She started working as a chemist in 1946 just to earn enough money to go to medical school, to fulfill her childhood dream of becoming a doctor. She soon fell in love with the work, though, which combined her interests in science and textiles.

One of very few female chemists working at Dupont, Stephanie was passionate about discovering new ways of working with synthetic fibers. She volunteered in 1964 for a project none of her colleagues seemed interested in: searching for a strong but lightweight fiber to use in tires.

While experimenting, Stephanie created a strange solution that was very different from ones she’d created before. It should have been a clear, thick fluid, like nylon polymer, but instead was thin and cloudy. “I think someone who wasn’t thinking very much or just wasn’t aware or took less interest in it, would have thrown it out.” But her curiousity and passion for discovery won out.

“I discovered over the years that I seem to see things that other people did not see. If things don’t work out I don’t just throw them out, I struggle over them, to try and see if there’s something there.”

The next step in the process of creating fibers from this solution required a machine called a spinneret, which was run by her coworker Charles Smullen. At first, he refused to spin the solution, thinking it would harm the machine. After much persuasion, Stephanie convinced him to run her solution.

They were amazed when the new fiber came back: it would not break when nylon typically would, and had a stiffness at least nine times greater than anything she’d made before! She and her supervisors immediately recognized the significance of her discovery, and the company set to work creating applications for this incredible new fiber.

Besides bullet-proof vests, the tough, heat-resistant fiber has since found over 200 applications. Today it’s used in products as diverse as fiber-optic cables, aircraft parts, canoes, brake linings, space vehicles, boats, parachutes, skis, and building materials.

The most famous application, of course, is the Kevlar vest. Thousands of lives have been saved by the bullet-stopping fiber. One Viriginia police officer even had Kwolek autograph the bulletproof vest that saved his life.

“I feel very lucky. So many people work all their lives and they don’t make a discovery that’s of benefit to other people.”

Stephanie Kwolek has received many awards and acknowledgments for her discoveries:

Award from the ACS for “Creative Invention” in 1980

Fourth woman to be added to the National Inventors Hall of Fame in 1995

National Medal of Technology in 1996

Perkin Medal from the American Chemical Society in 1997

Added to the National Women’s Hall of Fame in 2003

Today she is retired as a research associate for DuPont, but she still consults for the company. She also serves on both the National Research Council and the National Academy of Sciences.

“I think you have to inspire young people to believe in themselves and not to fear thinking differently.”